1. Field of the Invention
The present invention relates to a honeycomb structure and a method for manufacturing the honeycomb structure.
2. Discussion of the Background
Particulate matters such as soot (hereinafter, also referred to as PMs) are contained in exhaust gases discharged from an internal combustion engine such as a diesel engine, and in recent years, these PMs have raised serious problems as contaminants harmful to the environment and the human body.
For this reason, various filters using ceramics honeycomb filters including cordierite, silicon carbide or the like have been proposed as filters that capture PMs in exhaust gases to purify the exhaust gases. Moreover, various filters of a lamination type, manufactured by laminating lamination members having through holes therein, have been proposed (for example, see WO 2005/000445A).
FIG. 1A is a perspective view that schematically illustrates one specific example of such a lamination-type honeycomb filter which is formed by laminating lamination members, each including a sheet-shaped inorganic fiber aggregated body with through holes, and FIG. 1B is an A-A line cross-sectional view of FIG. 1A. FIG. 1C is an enlarged cross-sectional view of a portion illustrated by B in FIG. 1B.
A honeycomb filter 100 has a cylindrical structure in which a number of cells 111 having either one of the ends sealed are longitudinally placed in parallel with each other with a wall portion 113 therebetween.
In other words, as illustrated in FIG. 1B, each of the cells 111 has either one of the end corresponding to the inlet side or the outlet side of exhaust gases sealed, so that exhaust gases, introduced into one cell 111, are allowed to flow out from another cell 111, after always having passed through the wall portion 113 separating the cells 111; thus, the wall portion 113 is allowed to function as a filter.
As illustrated in FIGS. 1A and 1B, the honeycomb filter is formed as a laminated body by laminating lamination members 110a having a sheet shape with a thickness of 0.1 to 20 mm, and the lamination members 110a are laminated, with through holes superposed on one another in the longitudinal direction.
Here, the state in which the through holes are laminated so as to be superposed on one another refers to a state in which the through holes formed in the adjacent lamination members are superposed successively so as to communicate with each other.
Moreover, a lamination member for an end portion 10b having through holes formed in a checkered pattern therein is laminated on each of the two end portions thereof so that either one of the ends of each of the cells 111 is sealed by the lamination member for an end portion 10b. 
In order to form the respective lamination members into a laminated body, the lamination members 110a and the lamination member for an end portion 10b are laminated in a casing (metal tube-shaped (cylindrical) body) to be attached to an exhaust-gas pipe, and pressure is applied thereto. Thus, a honeycomb filter 100 is formed.
When an exhaust-gas purifying filter including a honeycomb filter having this structure is installed in an exhaust passage of an internal combustion engine, PMs in exhaust gases discharged from the internal combustion engine are captured by the wall portions 113 while passing through this honeycomb filter so that the exhaust gases are purified.
The contents of WO2005/000445A are incorporated herein by reference in their entirety.